update Inter google font embed link to include italics

[stefanprobst]

the current Inter embed link https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap does not include an "italic" style.

the current official link is: https://fonts.googleapis.com/css2?family=Inter:ital,opsz,wght@0,14..32,100..900;1,14..32,100..900&display=swap

note that Inter on google fonts was recently changed: there is no longer a "slnt" axis in the variable font, but a separate "italic" style.

[stefanprobst]

it seems that currently, italics are only displayed because of css font-synthesis setting. when setting font-synthesis: none no italics are visible.